Corrosion products removal deaerator



C. l. BAKER CORROSION PRODUCTS REMOVAL DEAERATOR Sept. 17 1963 Filed July 15, 1960 EATI N WATE 2 IN VEN TOR. 0/4/24 5.: 1. 54x52- hLS HTTOPA/E7Gi CORROSION PRODUCTS REMOVAL DEAERATOR Charles I. Baker, Lorain, Ohio; Lissa B. Darling, administratrix of said Charles I. Baker, deceased, assignor, by

mesne assignments, to A. M. Castle & (30., Franklin Park, 111., a corporation of Illinois Filed July 15, 1960, Ser. No. 43,043 Claims. (Cl. 55-164) This invention relates to hot water heating systems, and more particularly to apparatus for removing corrosion accumulations in such systems.

A direct fired hot water heating system can have within the heating boiler water leaks that may not be noticed for a long time because the leakage is carried 01f with the heating gases. Nevertheless, considerable raw makeup water would be used to compensate for the leakage and that water would contain its normal concentration of dissolved oxygen, which would corrode the heating system. Such a system generally uses a high level expansion tank vented to the atmosphere. If the heating system uses a steam boiler and heat exchanger for heating the circulating hot water, the system may suffer iron corrosion accumulations even though there is no water leakage. This is because oxygen gets into the pipes from the compressed air that is used to maintain the air cushion in the sealed expansion tank that forms part of the system. The breathing in and out of tank water, due to intermittent heating, absorbs air in the expansion tank and carries it away, and the loss of air in the tank is replenished frequently. However, no mat ter how oxygen gains entrance into a hot water heating system, the resulting corrosion buildup will slow down water circulation and the system will become unsatisfactory.

It is among the objects of this invention to provide a deaerator which continually deaerates water in a hot water heating system to remove corrosion products, which is simple and automatic in operation, and which is relatively inexpensive and very eflicient.

In accordance with this invention, two tanks are located close together at different levels. The upper tank has an inlet designed to be connected to the cool water return line of a hot water heating system. The tank also has a water outlet at its bottom and a gas outlet at its top. The gas outlet is provided with check valve means constructed to allow only gases to escape from the tank. The lower tank is provided with an inlet and an outlet. The upper tank water outlet is connected by a drain condu-i-t to the lower tank inlet, and thedr-ain conduit contains a normally open valve. Connected with'the lower tank outlet is a normally idle pumphaving an outlet normally connected by a conduitwith the upper tank. The upper parts of the upper and lower tanks are connected by a pipe, in the upper end of which there is an upwardly opening check valve. The pump is started by means responsive to a predetermined high water level the pipe below its check valve, and the drain valve is at the same time, whereby a vacuum is created wer tank as water is pumped out of it. When 'tank is filled with water and a predetermined built up in it, water is diverted from the pump the hot water line of the heating system. ter level in the lower tank falls to a certain mpstops and the drain valve opens to in the upper tank. The water, which er tank from the return line to make up to the hot water line, is deaerated y the pump to the heating system.

" ent of the invention is illusdrawings, in which;

deaerator; and

3,104,163 Patented Sept. 17, 1963 FIG. 2 is an electric wiring diagram for the deaerator.

Referring to FIG. 1 of the drawings, water heated in any suitable manner circulates through a hot water line 1, also known as a water supply line, and suitable radiators (not shown) where it gives olf heat, and then returns through a return line 2 for reheating. In order to reduce corrosion in the heating system, the return line is provided with a diversion pipe 3 that leads through a manually operated valve 4 and a check Valve 5 to a re ducing valve 6, where the pressure is cut from the usual 25 pounds or so to about 12 pounds. A make-up line 7, normally closed by a manually operated valve 8 is connected into the system between the check valve and the reducing valve. The outlet of the reducing valve is connected by a throttling tube 9, having a fixed flow resistance, to an inlet 10 in the upper part of a deaer-ator housing.

The cleaerator housing is separated more or less cenmany by a horizontal partition wall 12 into an upper tank 13 and a lower tank 14. The upper tank has an outlet 15 at its bottom connected by a drain conduit 16 with an inlet 17 in the side of the lower tank. The drain conduit contains a normally open diaphragm valve 18, which is closed whenever suflicient water pressure is applied to the top of its diaphragm through a tube 19. The top of the upper tank has a gas outlet 21, to which a pipe 22 is connected. The outer end of the pipe is connected by an outwardly opening check valve 23 to a tube 24 that restricts flow of gas from the tank. Pipe 22 contains an inverted check valve 25, the vertically movable closure 26 of which normally rests on supports 27 because the restricted flow of gas through the valve is not rapid enough to lift the closure and close the valve. However, water starting to escape from the top of the tank will lift the closure and close the valve to prevent the water from leaving the tank.

Near the bottom of the lower tank, it is provided with an outlet 30 (that is connected by a conduit 31 to the outlet of a pump 32 driven by an electric motor 33. The pump outlet 34 is connected to a conduit 35 that leads to an inlet in the upper tank, which preferably is inlet 10. The drain valve tube 19 is connected to outlet 34 of the pump also, so that the pump pressure will be ap plied to the valve to close it. The pump conduit 35 contains a three-way diaphragm valve 36 having a normally open closure 37 and a nonmally closed closure 38. The first one allows water topass from the pump to the upper tank. When the valve is reversed by fluid pressure on its diaphragm, flow to the upper tank is cut oil and water from the pump is diver-ted through the valve past now open closure 38 to a conduit connected to hot water line 1 of the heating system. Conduit 39 contains a check valve, and it may also contain a manually operated valve 41. The top of the three-way valve 36 is connected by a tube 42 with theinside of the upper tank, so that when the water pressure in the upper tank reaches a predetermined point after the tank has been filled, the valve will be reversed.

The upper parts of the two tanks are connected by a gas transfer pipe 45 that preferably also extends down and into the lower part of the lower tank. Mounted in the upper end of this pipe is an upwardly opening check valve 46. A little ways below the valve an electrode 47 extends into the pipe, into which it is sealed. A similar electrode 48 may extend into the lower section of the pipe near its lower end, or it can project directly into the lower tank. The two electrodes are so positioned that the capacity of the lower tank above the level of the low electrode is greater than the capacity of the upper tank above the level of the high electrode. These two electrodes are in an electric circuit that controls the starting and stopping of the pump motor 33. The circuit is such that water in pipe 45 must rise high enough to cover both electrodes to close the motor circuit so that the pump will start, and the water level then must fall below the lower electrode before the pump will stop.

The control circuit is shown in FIG. 2. It includes a relay that is a commercial item, which can be bought from the Mercoid Corporation. The relay has a core 50 that is provided with parallel legs. Encircling the lower part of one leg is a wire coil 51 that is connected by wires 52 and 53 in a three wire electric circuit. Wire 52 is connected by another wire 54 to one terminal of a normally open mercury switch 55, the opposite terminal of which is connected by a Wire 56 to a solenoid coil 57 connected to the third wire 58 of the main circuit. The switch is carried by the outer end of an arm 59 that is pivoted on a horizontal axis at 65} to the other leg of the core. The inner end of the arm rigidly supports a Wire coil 61 that loosely encircles the first leg of the core close enough to coil 51 below it for electrical current to be induced in the upper coil by coil 51. The high and low electrodes 47 and 48 are connected by wires 62 and 63, respectively, to this coil, and the upper electrode also is connected by a wire 64 to one terminal of a second normally open mercury switch 65 on the outer end of arm 59. The other terminal of this switch is grounded by a wire 66. Coil 61 weighs enough to normally hold the two mercury switches in their upper position, in which they are open.

When water from return line 2 causes the water in the deaerator tanks and gas transfer pipe 45 to rise high enough to cover high electrode 47, the water forms a conductor between the high and low electrodes and thereby completes a circuit through upper coil 61. As soon as that is done, electric current is induced in the upper coil by the constantly energized lower coil 51, and the coil windings are such that the upper coil is repulsed and tilts arm 59 in the opposite direction to cause the two mercury switches to descend and close. Switch 55 closes a circuit through solenoid 57, which then draws in its core 67 to close three normally open switches 68, 69 and 70 so that motor 33 will start. The closed upper meroury switch 65 connects upper coil 61 with ground and thereby forms a holding circuit through wire 64, the coil, wire 63, lower electrode 48 and the water that covers that electrode. Consequently, the holding circuit will function to maintain coil 61 in its upper position after the water in pipe 45 has dropped below high electrode 47 and until the water in the lower tank falls below the low electrode. The holding circuit then will open, arm 59 will tilt in the opposite direction, the mercury switches will open, solenoid 57 will be deenergized and a spring 71 will open the pump motor switches.

In the operation of this apparatus, Water diverted into the deaerator from the cool Water return line 2 enters the upper tank 13 and water flows down into the lower tank through drain conduit 16 until the lower tank 14 is filled and the upper tank and pipe 45 have been filled to the level of high electrode 47. At that moment the circuit between the high and low electrodes is closed by the water and pump 32 starts to operate, which causes drain valve 18 to close. Water is pumped from the lower tank through conduit 35 to inlet of the upper tank. This lowers the water level in the lower tank so that the water in pipe 45 drops down into the lower tank. Of course, no Water or gas can flow down through the pipe from the upper tank because check valve 46 will prevent it. The water level in the upper tank rises until it fills the tank and closes check valve 25, and then the water pressure builds up until it is great enough to reverse threeway valve 36. However, the pump continues to operate, so it now pumps water from the lower tank out through conduit 39 to the hot water line 1. This continues until the water level in the lower tank and pipe 45 falls below low electrode 48, whereupon the pump stops and drain valve 18 opens.

While water was being pumped out of the lower tank, a high vacuum was created in it and gases from the water were released into the evacuated zone. When the pump stops, water in the upper tank starts to flow through conduit 16 into the lower one and a vacuum therefore develops in the top of the upper tank. This vacuum is even greater than the one in the lower tank, due to the difference in the water levels. During this period gas is drawn from the lower tank up through the gas transfer pipe 45 and check valve 46 into the top of the upper tank. By the time the lower tank has been filled with water from the upper tank, the water level in the latter will be several inches below the high electrode 47.

Now a quiet period occurs while water flows into the upper tank from return line 2. Because this water enters an area of high vacuum, the dissolved gases in it are set free as millions of tiny bubbles which rise to the surface of the water and break. Throttling tube 9 has a high enough resistance to require several minutes to raise the water level in the deaerator to the point where it will engage the high electrode 47 and start the pump operating again to repeat the cycle just described. The water rising in the upper tank forces the liberated gases out through pipe 22 and check valve 23 to atmosphere. Before the water entering from the return line has passed through the deaerator and been pumped back into flow line 1, it is well deaerated. This not only reduces further corrosion in the heating system, but it also will soon remove existing corrosion accumulations. Such accumulations are removed because they are primarily ferric hydroxide. Deaerated water, because of its afiinity for oxygen, will effect conversion of the ferric hydroxide to ferrous hydroxide, which is soluble in the water.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustnated and described What I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention maybe practiced otherwise than as specifically illustrated and described.

I claim:

1. A deaerator for a liquid-conducting system having two liquid-conducting lines, said deaerator comprising an upper tank provided with an inlet adapted to receive liquid from one of said lines, the tank having a liquid outlet at its bottom and a gas outlet at its top, check valve means constructed to allow only gases to escape through said gas outlet, 21 lower tank provided with an inlet and an outlet, a drain conduit connecting the upper tank liquid outlet with the lower tank inlet, a normally open valve in the drain conduit, a normally idle pump connected with said lower tank outlet and having an outlet, a conduit normally connecting the pump outlet with the upper tank, a three-way valve in said conduit normally allowing flow of liquid therethrough, a pipe connecting the upper parts of the upper and lower tanks, an upwardly opening check valve in the upper end of said pipe, means responsive to a. predetermined high liquid level in said pipe below its check valve for starting the pump and closing said drain val means responsive to a predetermined liquid pressure upper tank when filled for reversing said threeto divert liquid from the pump conduit to the o liquid-conducting lines, and means responsiv determined low liquid level in the lower tank. the pump and opening the drain valve.

2. A deaerator for a liquidconductin two liquid-conducting lines, said deac upper tank provided with an inle uid from one of said lines, the at its bottom and constructed to all outlet, a lower a drain conduit connecting the upper tank liquid outlet with the lower tank inlet, a normally open valve in the drain conduit, a normally idle pump connected with said lower tank outlet and having an outlet, a conduit normally connecting the pump outlet with the upper tank, a threeway valve in said conduit normally allowing flow of liquid therethrou gh, fluid pressure responsive diaphragms for reversing said drain valve and three-way valve, a tube connecting the pump discharge with the drain valve diaphragm, a tube connecting the upper tank with the threeway valve diaphragm, a pipe connecting the upper parts of the upper and lower tanks, an upwardly opening check valve in the upper end of said pipe, means responsive to a predetermined high liquid level in said pipe below its check valve for starting the pump, a conduit connecting the three-way valve when reversed to the other of said liquid-conducting lines and means responsive to a predetermined low liquid level in the lower tank for stopping the pump.

3. A deaerator comprising an upper tank provided with an inlet, an inlet conduit for delivering liquid to be deaerated to said tank inlet, the tank having a liquid outlet at its bottom and a gas outlet at its top, check valve means constructed to allow only gases to escape through said gas outlet, a lower tank provided with an inlet and an outlet, a drain conduit connecting the upper tank liquid outlet with the lower tank inlet, a normally open valve in the drain conduit, a normally idle pump connected with said lower tank outlet and having an outlet, a conduit normally connecting the pump outlet with the upper tank, a pipe connecting the upper parts of the upper and lower tanks, an upwardly opening check valve in the upper end of said pipe, a high electrode in said pipe below its check valve, a low electrode normally in communication with liquid in the lower tank, an electric circuit containing said electrodes and adapted to be closed when liquid rises in said pipe to the high electrode for starting the pump and keeping it operating until the liquid in the lower tank falls below said lower electrode, means for closing the drain valve when the pump starts and opening the drain valve when the pump stops, and means responsive to a predetermined liquid pressure in the upper tank when filled for diverting liquid from said pump conduit to a predetermined location.

4. A deaerator for a liquid-conducting system having two liquid-conducting lines, said deaerator comprising an upper tank provided with an inlet, an inlet conduit for connecting one of said lines with said tank inlet, the tank having a liquid outlet at its bottom and a gas outlet at its top, check valve means constructed to allow only gases to escape through said gas outlet, a lower tank provided with an inlet and an outlet, a drain conduit connecting the upper tank liquid outlet with the lower tank inlet, a normally open valve in the drain conduit, a normally idle pump connected with said lower tank outlet and having an outlet, a conduit normally connecting the pump outlet with the upper tank, a pipe connecting the upper parts of the upper and lower tanks, an upwardly opening check valve in the upper end of said pipe, means responsive to a predetermined high liquid level in said pipe below its check valve for starting the pump and closing said drain valve, means responsive to a predetermined liquid pressure in the upper tank when filled for diverting liquid from said pump conduit to the other of said liquid-conducting lines, and means responsive to a predetermined low liquid level in the lower tank for stopping the pump and opening the drain valve.

5. A deaerator according to claim 4, including flow resistance means in said inlet conduit for reducing the flow of liquid entering said upper tank inlet to a predetermined rate.

References Cited in the file of this patent UNITED STATES PATENTS 2,223,112 Lear Nov. 26, 1940 2,339,369 Baker Jan. 18, 1944 2,605,856 Kirkpatrick et al Aug. 5, 1952 2,735,623 Baker Feb. 21, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Noe $104,163 September 17, 1963 Charles 1. Baker; Lisa B Darling administ-ratrix of said Charles 1. Baker deceased s in the above numbered pat- It is hereby certified that error appear Patent should read as ent requiring correction and that the said Letters corrected below.

Column 2 line 39 for "outlet" read inlet Signed and sealed this 31st day of March 1964 (SEAL) EDWARD J. BRENNER ERNEST W0 SWIDER Commissioner of lalmnm Attesting Officer 

1. A DEAERATOR FOR A LIQUID-CONDUCTING SYSTEM HAVING TWO LIQUID-CONDUCTING LINES, SAID DEAERATOR COMPRISING AN UPPER TANK PROVIDED WITH AN INLET ADAPTED TO RECEIVE LIQUID FROM ONE OF SAID LINES, THE TANK HAVING A LIQUID OUTLET AT ITS BOTTOM AND A GAS OUTLET AT ITS TOP, CHECK VALVE MEANS CONSTRUCTED TO ALLOW ONLY GASES TO ESCAPE THROGUH SAID GAS OUTLET, A LOWER TANK PROVIDED WITH AN INLET AND AN OUTLET, A DRAIN CONDUIT CONNECTING THE UPPER TANK LIQUID OUTLET WITH THE LOWER TANK INLET, A NORMALLY OPEN VALVE IN THE DRAIN CONDIUT, A NORAMLLY IDLE PUMP CONNECTED WITH SAID LOWER TANK OUTLET AND HAVING AN OUTLET, A CONDUIT NORMALLY CONNECTING THE PUMP OUTLET WITH THE UPPER TANK, A THREE-WAY VALVE IN SAID CONDIUT NORMALLY ALLOWING FLOW OF LIQUID THERETHROUGH, A PIPE CONNECTING THE UPPER PARTS OF THE UPPER AND LOWER TANKS, AN UPWARDLY OPENING CHECK VALVE IN THE UPPER END OF SAID PIPE, MEANS RESPONSIVE TO A PREDETERMINED HIGH LIQUID IN SAID PIPE BELOW ITS CHECK VALVE FOR STARTING THE PUMP AND CLOSING SAID DRAIN VALVE, MEANS RESPONSIVE TO A PREDETERMINED LIQUID PRESSURE IN THE UPPER TANK WHEN FILLED FOR REVERSING SAID THREE-WAY VALVE TO DIVERT LIQUID FROM THE PUMP CONDUIT TO THE OTHER OF SAID LIQUID-CONDUCTING LINES, AND MEANS RESPONSIVE TO A PREDETERMINED LOW LIQUID LEVEL IN THE LOWER TANK FOR STOPPING THE PUMP AND OPENING THE DRAIN VALVE. 